Page 125 of 203

125n
IndexDataTechnologyRepairsCar careControlsOverview
To maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer. BMW tests and approves
wheel/tire combinations. Refer to
page 129.DOT Quality GradesTreadwear
Traction AA A B C
Temperature A B C
All passenger car tires must
conform to Federal Safety
Requirements in addition to these
grades.< Tread wearThe tread wear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would
wear one and one-half (1g) times as
well on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.
TractionThe traction grades, from highest to
lowest, are AA, A, B, and C.
Those grades represent the tire's ability
to stop on wet pavement as measured
under controlled conditions on speci-
fied government test surfaces of asphalt
and concrete. A tire marked C may have
poor traction performance.
The traction grade assigned to
this tire is based on straight-
ahead braking traction tests, and does
not include acceleration, cornering,
hydroplaning, or peak traction charac-
teristics.< TemperatureThe temperature grades are A (the
highest), B, and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause
the material of the tire to degenerate
and reduce tire life, and excessive
temperature can lead to sudden tire
failure. The grade C corresponds to a
level of performance which all
passenger car tires must meet under
the Federal Motor Vehicle Safety Stan-
dard No. 109. Grades B and A repre-
sent higher levels of performance on
the laboratory test wheel than the
minimum required by law.
The temperature grade for this tire
is established for a tire that is
properly inflated and not overloaded.
Excessive speed, under-inflation, or
excessive loading, either separately or
in combination, can cause heat buildup
and possible tire failure.< Uniform Tire Quality Grading Quality grades can be found where
applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Tread wear 200 Traction AA
Temperature A
Do not use retreaded tires. Driving
safety may be impaired by their
use. This is due to the possible varia-
tions in casing structures and, in some
cases, to their extreme age, which can
lead to a decrease in their durability.<
Tire replacement
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IndexDataTechnologyRepairsCar careControlsOverview
Wheel and tire combinations The right choice Use only tires approved by BMW.
Refer to the information beginning on
page 129.
Due to the high speeds this vehicle can
reach, the use of specific brands, spec-
ifications and sizes is mandatory.
Consult any BMW center for details.
Comply with local/national regulations.
The correct wheel-tire combina-
tion affects different systems such
as ABS, ATC and ASC+T/DSC. The
function of these systems is impaired if
improper wheel-tire combinations are
used.
For this reason, use only tires of the
same brand and tread pattern. In the
event of a flat tire, for example, remount
the approved wheel-tire combination as
soon as possible.<
Codes on tires and wheels The tire codes will aid you in selecting
the correct tire.
Codes on radial tires:
The speed rating indicates the approved
maximum speed for the tire.
Summer tires:
S = up to 112 mph (180 km/h)
T = up to 118 mph (190 km/h)
H = up to 130 mph (210 km/h)
V = up to 150 mph (240 km/h)
W = up to 167 mph (270 km/h)
Y = up to 187 mph (300 km/h)
ZR = over 150 mph (240 km/h) For example:
Nominal width
in mm
Aspect ratio in %
Radial tire code
Rim diameter in inches
Load rating
(not on ZR tires)
Speed rating
(before R on ZR tires)
205/60 R 15 91 W
Winter tires:
Q M+S = up to 100 mph (160 km/h)
T M+S = up to 118 mph (190 km/h)
H M+S = up to 130 mph (210 km/h)
Codes stamped on light-alloy wheels:
Protect tire valves from dirt by using
screw-on valve stem caps. Dirt in the
valves frequently leads to slow leaks. For example:
Rim width
in inches
Code letter for
flange type
Symbol for full-drop
center rim
Rim diameter in inches
Hump on the 2 rim shoulders
7 x 15 H 2
J
Page 197 of 203

Everything from A to Z
197n
IndexDataTechnologyRepairsCar careControlsOverview
Tire codes127
Tire damages124
Tire inflation
pressure28,124
Tire Pressure Control
(RDC)85,178
Tire pressure
monitoring85,178
Tire Quality Grading125
Tire replacement125,126
Tire specifications129
Tire tread124
Tools152
Torque184
Tow fittings168
Tow starting168
Towing168
Track185
Traction Control System,
refer to DSC79
Transmission64
Transporting children
safely58
Tread depth, tires124
Trip odometer73
Trunk38
Turn signal
indicator23,68,154
bulb replacement154
Turning radius185
Two-way radios123
U
Uniform Tire Quality
Grading125
Used batteries164 V
Vacuum cleaner,
connecting104
Vanity mirror51
bulb replacement158
Vehicle battery162,188
Vehicle care
exterior142
interior144
Vehicle Identification
Number (VIN)139
Vehicle immobilizer33
Vehicle painting142
Vehicle removal from
service147
Vehicle storage147
Vehicle weight186
Ventilation90,93,96
draft-free93,100
Vinyl upholstery, care144
Voice recognition24,25 W
Warning lamps20
Warning messages75
Warranty and Service Guide
(Canadian models)140 Washer fluids134
Washer nozzles134
Washer reservoir, filling134
Washing your car141
Water on roadways
deep water115
Waxing, paintwork143
Weights186
Wheel changing159
Wheel lug wrench159
Wheel rims127
Wheel stud wrench159
Wheelbase185
Wheels and tires127,129
Width185
Windows, convenience
operation34
Windshield washer nozzle
adjustment134
Windshield washer reservoir,
filling134,187
Windshield wiper68
blade replacement152
Winter operation121
Winter tires127,128
Wiper blade
replacement152
Wiper system68
Work in the engine
compartment130
X
Xenon lamp154,180